Phenotypic Characterization and Preliminary In Vivo Evaluation of a Locally Isolated Klebsiella pneumoniae Bacteriophage.
- 1Research Institute for Biological Safety Problems, National Holding QazBioPharm, LLP, Gvardeisky 080409, Kazakhstan.
- 2Faculty of Veterinary Medicine and Zooengineering, Kazakh National Agrarian Research University, Abay Avenue 8, Almaty 050010, Kazakhstan.
Abstract
Drug-resistant Klebsiella pneumoniae is a serious clinical problem, and bacteriophages are being investigated again as antibacterial agents. This study describes the phenotypic characterization and a preliminary in vivo evaluation of vB_Kpn_NIIPB-V0006, a bacteriophage isolated locally on a drug-resistant clinical K. pneumoniae strain. The genome of the phage was not sequenced. It has therefore not been screened for lysogeny-associated, toxin, virulence or antimicrobial resistance genes, and the results below describe what the phage does, not whether it is suitable for therapy. We assessed plaque morphology, specific lytic activity, titer, host range on a limited non-target panel, particle morphology, adsorption, one-step growth, chloroform exposure, the frequency of phage-resistant host variants, endotoxin reduction, short-term safety in mice and antibacterial effect in guinea pigs. The phage lysed the target strain, with an Appelman activity of 10⁻⁸ and a titer of 1.7 × 10¹¹ PFU/mL. Processing with 1-octanol lowered endotoxin content from 1200 to 12 EU/mL and preserved 80% of infective activity. Mice given the preparation intraperitoneally showed no mortality and no visible acute toxicity over 14 days. In guinea pigs with systemic K. pneumoniae infection, survival was the primary outcome: 0.5 mL three times daily gave 6/6 survivors against 1/6 in untreated controls (p = 0.015). Splenic bacterial burden, a secondary outcome, was also lower in that group (2.64 against 4.41 log₁₀ CFU/g). Two features of the design bias this second comparison in favor of treatment, since survivors and non-survivors were sampled at different times, and phage being carried over into the plating step is likely to have lowered colony counts. The 1.77 log₁₀ difference should therefore be read as an upper bound. The phage merits further study, but whole-genome sequencing, confirmation of the host species, host-range testing against diverse clinical isolates and a controlled comparison with antibiotic treatment are all needed before any therapeutic claim can be made.
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BibTeX
@article{sarmykova2026phenotypic,
title = {{Phenotypic Characterization and Preliminary In Vivo Evaluation of a Locally Isolated Klebsiella pneumoniae Bacteriophage.}},
author = {Makhpal Sarmykova and Akbope Abdykalyk and Nazym Syrym and Bolat Yespembetov and Aktoty Anarbekova and Sabira Alpysbayeva and Azamat Abdimukhtar and Alinur Toleukhan and Kali Tileukhanov and Yeldos Serikbay and Bekzat Yerzhigit and Nazym Akimzhan and Kuandyk Zhugunissov and Sergazy Nurabayev},
journal = {Biotech (Basel (Switzerland))},
year = {2026},
month = sep,
doi = {10.3390/biotech15040084},
url = {https://europepmc.org/article/MED/42930062},
note = {CC BY},
}
RIS
TY - JOUR
TI - Phenotypic Characterization and Preliminary In Vivo Evaluation of a Locally Isolated Klebsiella pneumoniae Bacteriophage.
AU - Makhpal Sarmykova
AU - Akbope Abdykalyk
AU - Nazym Syrym
AU - Bolat Yespembetov
AU - Aktoty Anarbekova
AU - Sabira Alpysbayeva
AU - Azamat Abdimukhtar
AU - Alinur Toleukhan
AU - Kali Tileukhanov
AU - Yeldos Serikbay
AU - Bekzat Yerzhigit
AU - Nazym Akimzhan
AU - Kuandyk Zhugunissov
AU - Sergazy Nurabayev
PY - 2026
DA - 2026/09/29
JO - Biotech (Basel (Switzerland))
DO - 10.3390/biotech15040084
UR - https://europepmc.org/article/MED/42930062
AB - Drug-resistant Klebsiella pneumoniae is a serious clinical problem, and bacteriophages are being investigated again as antibacterial agents. This study describes the phenotypic characterization and a preliminary in vivo evaluation of vB_Kpn_NIIPB-V0006, a bacteriophage isolated locally on a drug-resistant clinical K. pneumoniae strain. The genome of the phage was not sequenced. It has therefore not been screened for lysogeny-associated, toxin, virulence or antimicrobial resistance genes, and the results below describe what the phage does, not whether it is suitable for therapy. We assessed plaque morphology, specific lytic activity, titer, host range on a limited non-target panel, particle morphology, adsorption, one-step growth, chloroform exposure, the frequency of phage-resistant host variants, endotoxin reduction, short-term safety in mice and antibacterial effect in guinea pigs. The phage lysed the target strain, with an Appelman activity of 10⁻⁸ and a titer of 1.7 × 10¹¹ PFU/mL. Processing with 1-octanol lowered endotoxin content from 1200 to 12 EU/mL and preserved 80% of infective activity. Mice given the preparation intraperitoneally showed no mortality and no visible acute toxicity over 14 days. In guinea pigs with systemic K. pneumoniae infection, survival was the primary outcome: 0.5 mL three times daily gave 6/6 survivors against 1/6 in untreated controls (p = 0.015). Splenic bacterial burden, a secondary outcome, was also lower in that group (2.64 against 4.41 log₁₀ CFU/g). Two features of the design bias this second comparison in favor of treatment, since survivors and non-survivors were sampled at different times, and phage being carried over into the plating step is likely to have lowered colony counts. The 1.77 log₁₀ difference should therefore be read as an upper bound. The phage merits further study, but whole-genome sequencing, confirmation of the host species, host-range testing against diverse clinical isolates and a controlled comparison with antibiotic treatment are all needed before any therapeutic claim can be made.
SN - 2673-6284
ER -